Operating state variables which describe the rotation movement of the rotating structural element, such as rotary position, angular speed, angular acceleration etc., are of particular interest in the present case. Therefore, the invention relates primarily to a measuring device which detects at least one operating state variable which describes the rotation movement.
A measuring device for identifying rotation is disclosed in European Patent Specification EP 1 342 633 B1. The measuring device comprises a current generator, which has a stator and a rotor, a power supply circuit and a magnetic field sensor. In this case, the rotor, which is also called an encoder ring, encoder plate or incremental wheel in this context, has a large number of opposed magnet poles which alternate with one another in a direction over the circumference of the rotor, and a multipart ring element which is produced from a magnetic material is provided as the stator. The magnetic field sensor is arranged in a fixed position relative to the stator and is fixed either to said stator or to a support element for the stator. The magnetic field sensor, which is supplied with power by means of the generator and the power supply circuit, is used to register the alternating passage of the magnet poles of the rotor past the magnetic field sensor during rotation of the rotor, as a result of which the presence of a rotation movement is detected. The measuring device can be used, for example, as a component for an anti-lock brake system in the automotive sector. However, this considered to be disadvantageous since because the production costs are regarded as being excessively high.